Clicking Noise in Macbook Air

Starting just a couple of days ago, theres a very quiet clicking noise coming from inside my Macbook Air. The computer works just fine but there's a strange clicking noise coming from around the A key on the left side of the keyboard. It occurs freqently in about five second intervals. Every so often if I move my laptop, it'll make a really loud sound from the same part that lasts about 3 seconds. Has this happened to anyone? And what should I do about it?

Thanks.